17.4. Named SQL Queries

We discussed how to write named JDOQL queries in
Section 11.10, “Named Queries”. Named queries, however,
are not limited to JDOQL. By setting the query
element's language attribute to
javax.jdo.query.SQL, you can define a named SQL query. A
named SQL query within a class element queries for
instances of that class; a named SQL query outside of a class
element acts as a column data projection.